GENETICS AND DNA

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GENETICS AND DNA

• Genetics is the study of how traits are passed
  from parent to offspring.
• Genes - sections of the chromosomes found in
  cells control these traits.
• DNA is a molecule located on a chromosome that
  makes up genes and determines traits of all
  living things.

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Genome

• Genome Complete complement of an organisms DNA.
• Includes genes (control traits) and non-coding
  DNA organized in chromosomes.

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CHROMOSOMESLocated in Nucleus Split and
Produce New Cells Contain Genes

• BODY CELLS
• Make up most of the bodys tissues and organs
• 2 of each chromosomes for a total of 46

• SEX CELLS
• Can be a sperm cell (male) or an egg cell
  (female)
• Only 1 kind of each chromosome half as many as
  chromosomes in body cells

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Genes

• Eukaryotic DNA is organized in chromosomes.
• Genes have specific places on chromosomes.

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STRUCTURE of DNA

• Holds information needed for cell function and
  carries information needed to make proteins.
• Model looks like a ladder in a twisted shape.
• DNA backbone (or sides) are made up of
  alternating sugars and phosphates.
• Rungs of the ladder are composed of 4 nitrogen
  bases (adenine, thymine, cytosine, guanine) which
  are joined together in a specific order (via a
  covalent bond which is very strong).

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STRUCTURE of DNA

• This order is based on our genetic history, and
  makes up our genetic characteristics (eye, hair
  color ear shape and size, etc.).
• These 4 bases form a code which spells out a
  certain message.
• This code is similar to the way the 26 letters in
  our alphabet combine to form words.

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DNA STRAND

• A ALWAYS pairs up with T
• C ALWAYS pairs up with G
• A-T C-G

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DNA -vs- RNA

• DNA
• Sugar deoxyribose
• Nitrogen bases
• a. Adenine
• b. Guanine
• c. Cytosine
• d. Thymine
• Double stranded molecule

• RNA
• Sugar ribose
• Nitrogen bases
• a. Adenine
• b. Guanine
• c. Cytosine
• d. Uracil
• Single stranded

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The making of RNA

• RNA is formed from DNA The strands split at the
  (weak) hydrogen bonds where needed to make mRNA.
  (messenger RNA)
• The thymine (T) in DNA is replaced with uracil
  (U).
• This process takes place in the ribosomes within
  a cell.
• Process is referred to as transcription.

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TRANSLATIONlanguage of amino acids creation
of a protein

• mRNA is the blueprint that tells the order of
  amino acids
• mRNA is the CODE composed of a single strand of
  nucleotides (A,U,C,G)
• Nucleotides divided into patterns of 3 letters in
  a row (triplet codon) 1 amino acid
• Each codon forms long chain to produce proteins.
• STOP codons (UAA, UAG, UGA) tell ribosomes when
  to stop making a proteins

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From Genes to Proteins